As a basic principle, dental prosthetic devices, especially partial and hybrid dental prosthetic devices, must be secured via suitable interconnecting elements on anchor teeth and/or crowns, hereinafter referred to as anchor teeth. This is typically effected via metallic construction elements, mainly in the form of connecting pieces between natural teeth structure and dental prosthetic devices, whereby principally high value stainless steel coatings, titanium, nonferrous metals are deployed for such purposes, with these materials forming two compatibly configured interconnecting elements namely, a positive coupling piece and a negative coupling piece.
Such metallic configurations bring with them the disadvantage that the biocompatibility thereof can be improved.
EP-A1-0 887 049 discloses a dental connecting apparatus which, in lieu of a metallic base construction, realizes the connection via ceramic material which is applied either as the exclusive material or as a coating. Coatings have, on the other hand, the disadvantages that the typically different heat expansion coefficients between metals and a ceramic require very careful application of the ceramic coating and, in view of the substantially brittle characteristic of the ceramic, the coating must be markedly thick if it is to have good durability.
The above-noted publication describes, in any event, a solution whereby conventional positive coupling pieces and negative coupling pieces comprised of ceramic filling material are presented as the improved technical solution.
Moreover, the above-noted publication discloses as well the provision of a synthetic material or plastic coating on the ceramic material in order to improve the slide capability of the positive coupling pieces and negative coupling pieces. This solution has the disadvantage that the synthetic material coating, which has only a negligible secure holding characteristic, precisely in connection with its deployment on the positive coupling piece leads to a weakening of the material thickness available for assuring the tenaciousness of the piece, so that the positive coupling piece is in danger of breaking. It is, therefore, not surprising that this solution has not found wide usage.
It has also already been suggested, in lieu of the afore-described solutions, to improve the aesthetic appearance of the dental prosthetic devices with pure mixture materials for metallic connecting pieces between natural teeth structure and dental prosthetic devices, whereby the functional portions that is, the areas of the positive coupling pieces and negative coupling pieces which are disposed in opposition to one another are comprised of substantial amounts of metallic material. In this manner, the bio-compatibility is somewhat improved; a completely sealed configuration of the coupling securement, which would seal off the metallic outer surfaces, has not yet, however, been achieved in connection with this solution.